noun
the three urban prefectures (Tokyo, Kyoto, Osaka)
Historical term referring to the three prefectures of Tokyo, Kyoto, and Osaka before Tokyo became a metropolitan prefecture in 1943.
See also: 府
戦前の日本では、三府は東京、京都、大阪を指した。
In prewar Japan, the three urban prefectures referred to Tokyo, Kyoto, and Osaka.